Yao Zhu1, Jie-Ming Lu1, Zhe-Bin Yu1, Die Li1, Meng-Yin Wu1, Peng Shen2, Hong-Bo Lin2, Jian-Bing Wang3, Kun Chen4. 1. Department of Epidemiology and Biostatistics, School of Public Health, Zhejiang University, Hangzhou, China. 2. Department of Chronic Disease and Health Promotion, Yinzhou District Center for Disease Control and Prevention, Ningbo, China. 3. Department of Epidemiology and Biostatistics, School of Public Health, Zhejiang University, Hangzhou, China; Research Center for Air Pollution and Health, Zhejiang University, Hangzhou, China. Electronic address: wangjianbing@zju.edu.cn. 4. Department of Epidemiology and Biostatistics, School of Public Health, Zhejiang University, Hangzhou, China; Research Center for Air Pollution and Health, Zhejiang University, Hangzhou, China; Cancer Institute, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. Electronic address: ck@zju.edu.cn.
Abstract
BACKGROUND AND AIMS: The relationship between serum total cholesterol (TC) and mortality remains inconsistent. Additionally, intra-individual variability of cholesterol has been of increasing interest as a new indicator for health outcomes. We aimed to examine the association between TC and its variability and risk of mortality. METHODS AND RESULTS: We performed a retrospective cohort study with 122,645 individuals aged over 40 years in Ningbo, China. The intra-individual variability was calculated using four metrics including standard deviation, coefficient variation, variation independent of mean and average successive variability. Hazard ratios and 95% confidence intervals were estimated for the associations of baseline and variability in TC with risk of mortality by Cox proportional hazards regression models. During 591,585.3 person-years of follow-up, 4563 deaths (including 1365 from cardiovascular disease, 788 from stroke and 1514 from cancer) occurred. A U-shaped association was observed for baseline TC level and risk of total, cardiovascular and cancer mortality, with lowest mortality at 5.46 mmol/L, 5.04 mmol/L and 5.51 mmol/L, respectively. As compared with subjects with TC variability in the lowest quartile, individuals in the highest quartile had 21% higher risk of all-cause mortality (HR = 1.21, 95% CI: 1.05 to 1.40), and 41% higher risk of CVD mortality (HR = 1.41, 95%CI: 1.10 to 1.81). CONCLUSION: Both too low and too high baseline TC level were associated with higher risk of total, cardiovascular disease and cancer mortality. Variability of TC could be a risk factor of total and CVD mortality, independent of mean TC level. Future studies are needed to confirm these findings.
BACKGROUND AND AIMS: The relationship between serum total cholesterol (TC) and mortality remains inconsistent. Additionally, intra-individual variability of cholesterol has been of increasing interest as a new indicator for health outcomes. We aimed to examine the association between TC and its variability and risk of mortality. METHODS AND RESULTS: We performed a retrospective cohort study with 122,645 individuals aged over 40 years in Ningbo, China. The intra-individual variability was calculated using four metrics including standard deviation, coefficient variation, variation independent of mean and average successive variability. Hazard ratios and 95% confidence intervals were estimated for the associations of baseline and variability in TC with risk of mortality by Cox proportional hazards regression models. During 591,585.3 person-years of follow-up, 4563 deaths (including 1365 from cardiovascular disease, 788 from stroke and 1514 from cancer) occurred. A U-shaped association was observed for baseline TC level and risk of total, cardiovascular and cancer mortality, with lowest mortality at 5.46 mmol/L, 5.04 mmol/L and 5.51 mmol/L, respectively. As compared with subjects with TC variability in the lowest quartile, individuals in the highest quartile had 21% higher risk of all-cause mortality (HR = 1.21, 95% CI: 1.05 to 1.40), and 41% higher risk of CVD mortality (HR = 1.41, 95%CI: 1.10 to 1.81). CONCLUSION: Both too low and too high baseline TC level were associated with higher risk of total, cardiovascular disease and cancer mortality. Variability of TC could be a risk factor of total and CVD mortality, independent of mean TC level. Future studies are needed to confirm these findings.
Authors: Han-Wei Zhang; Victor C Kok; Shu-Chun Chuang; Chun-Hung Tseng; Chin-Teng Lin; Tsai-Chung Li; Fung-Chang Sung; Chi Pang Wen; Chao A Hsiung; Chung Y Hsu Journal: PLoS One Date: 2019-12-04 Impact factor: 3.240